Alison Carnwath, a high-profile serial director with a seat in the boardrooms of a number of major companies, has become a focus of discontent among investors after suffering an embarrassing protest vote by investors at hedge fund Man.

Some 33% of investors failed to support her re-election to the board of the hedge fund group at Tuesday's annual meeting. Shareholders who attended were reported to have criticised her lengthy tenure on the Man board and her performance at "another place".

That appears to be a reference to her role as chairman of the remuneration committee at Barclays bank. At the bank's AGM last week 22.5% failed to back her re-election to the board in protest at the £17m pay package handed to chief executive Bob Diamond– and the £5.7m tax bill the bank agreed to pay on Diamond's behalf..

Man held its annual meeting at a time when investors appear increasingly prepared to exercise their votes. They are under pressure from the government to clamp down on executive pay and hold companies to account.

Company directors usually expect near unanimous support at annual meetings but the introduction of annual votes on directors seems to be encouraging shareholders to take action against individuals.

Carnwath is one of the highest profile non-executive directors in FTSE 100 boardrooms and chairs the property company Land Securities. The 59-year- old, who read economics and German at Reading University, worked as an investment banker for more than 20 years before moving into some of the UK's biggest boardrooms.

In addition to Barclays, Land Securites and Man Group, she also sits on the board of the insurance group Zurich and US technology company Paccar.

She has previously held directorships at companies as diverse as Friends Provident, Glas Cymru and Gallaher. She also serves on the board of ISIS private equity partners, which owns the casualwear brand Fat Face and womenswear chain Bonmarché. Carnwath was chair of MF Global, the now-bankrupt brokerage, until March 2010.

The shareholder advisory body ISS had recommended to its clients – pension funds and other investors –to vote against her election to the board on the basis that she is no longer independent. Corporate governance guidelines say directors can no longer be independent if they have spent more than nine years in a boardroom. Carnwath has been at Man for 11 years.

ISS also highlighted that Carnwath's tenure on the board was "concurrent" with that of chief executive Peter Clarke, who has been under fire from some investors for the under-performance of the group.

To head off concerns about her lack of independence, Carnwath had stepped down as the senior independent director– a key point of contact for investors – in July 2011.

However, ISS noted that she remained a member of the remuneration committee and said it "does not consider her to be independent; she remains a member of the remuneration committee, which should be wholly independent".

Man insisted Carnwath was "unquestionably" independent.

Executive who agreed Diamond's £17.7m deal

To use Nick Clegg's words, Alison Carnwath is the embodiment of "crony capitalism" that allows a small group of City figures to set each other's pay and bonuses without having to worry about the real world.

Carnwath, 59, is one of two executives to serve on the remuneration committee of three FTSE 100 companies – Barclays, Man Group and Land Securities.

The government wants to ban executives at one company from setting pay at another. Shareholders have also begun to act against this cosy arrangement that lifts executive pay across the board, with a third of Man's shareholders failing to back Carnwath's re-election to the board after a 21% protest vote at Barclays last week. Carnwath was responsible for pushing through a £17.7m pay package for Barclays boss Bob Diamond and £7m for Man's chief executive Peter Clarke.

Investors have also complained that Carnwath, who has a holiday home in the Bahamas, does not have the best attendance record.

Pirc, the shareholder advisory body, urged investors to vote against Carnwath's reappointment at Barclays noting that she "missed three audit committee meetings". She earns £300,000 as chair of Land Securities, £158,000 from her role at Barclays and a further £100,000 at Man.